Poly(phenylene sulfide): Synthesis from 1,4-dibromobenzene and sodium sulfide

A new route to synthesize poly(p-phenylene sulfide) by nucleophilic substitution of 1,4-dibromobenzene with sodium sulfide in N-methylpyrrolidone is described. Kinetic evaluation shows the reaction to be of second order with two distinctive rate constant regimes. The first rate constant is higher and is operative until 50% conversion, whereas in the second regime (between 50 and 92% conversion) the rate is slower. The kinetics of this route is compared under identical conditions with the conventional synthesis based on 1,4-dichloro benzene and sodium sulfide.